Blue-red disazo dye and process of making same.



UNITED STATES PATENT OFFICE.

AUGUST LEOPOLD LASKA, OF OFFENBACH-ON-THE-MAIN, GERMANY, ASSIGNOR TO THE FIRM OF K. OEHLER, ANILIN- & ANILINFARBEN FABRIK, OF SAME PLACE.

BLUE-RED DISAZO DYE AND PROCESS OF MAKING SAME.

SPECIFICATION forming part of Letters Patent No. 679,974, dated August 6, 1901.

Application filed May 27, 1901. Serial No. 62,014. (No specimens.)

T0 at whom, it may concern:

Be it known that LAUGUST LEOPOLD LASKA, chemist, doctor of phiiosophy, residing at Obermainstrasse 35, OEenbach-on-the-Main, Germany, have invented new and useful Improvements in Bluish Claret Red Disazo Dyes, of which the following is a specification.

If benzoyl- 2:5 amidonaphthol 7 sulfonic acidis made toact uponintermediate products derived from paradiamins and the oXy-carboxylic acids of the benzene series, coloringmatters are obtained, dyeing unmordanted cotton in bluish-claret-red shades of good fastness, being especially distinguished from all other similar dyestuifs by their great fastness to light. In order to form such dyes, there may be employed as diamins benzidin, tolidin, dianisidin, para phenylendiamin, and as oxy-carboxylic acids those of the benzene and their homologues.

The following is an example of carrying out my invention, the parts being by weight: Dyestuff from Salicylic acid Benzidin Benzoy1-2: E-amidonaphthol-Tsulfonic acid.

eighteen parts of benzoyl-Z :5-amidonaphtholv 7-sulfonic acid, allow to stand for twenty-four hours in order to complete the reaction, then raise slowly the temperature up to 80.to 90 centigrade, precipitate with common salt, press, and dry. The coloring-matter thus obtained forms in its dry state a reddish blackbrown powder with a metallic luster, hardly soluble in cold and readily soluble in hot water, with a yellowish-red color and dyes unmordanted cotton a bluish claret red fast to light and washing.

What I claim, and desire to secure by Letters Patent, is

1. The herein-described process of production of claret-red disazo coloring-matters consistin g in the combination of the intermediate products from paradiamins and the oxy-car boxylic acids of the benzene series with benzoyl-amidonaphthol-sulfonic acid.

2. As newarticles of manufacture the bluishclaret-red disazo dyestuffs herein described resulting from the combination of the intermediate products from paradiamins and oxyoarboxylic acids with the benzoyl-2z5-amidonaphtl1ol-7-sulfonic acid of the formula NEED-Ca s hardly soluble in cold, readily soluble in hot water with a yellowish-red color and dyeing unmordanted cotton a bluish claret red.

3. As a new article of manufacture the dyestufi, the constitution of which is represented by the following scheme Salicy1ic acid Benzoy1-2: 5-amidonaphthol F-sulfonic acid AUGUST LEOPOLD LASKA.

Witnesses HERMANN WEIL, KARL SIEGLE.

son-1 Benzidin 

